The following paper deals with the cooling stack, which transfers the exhaust gases from the converter. This cooling stack is made of each other welded pipes, in which the water flows and cools the stack. The goal of this work is to determine the influences on the distribution of water in the individual tubes. This allows the optimization of the distribution system regarding the pressure loss and the uniformity of the water distribution. At the beginning of this work a theoretical overview on the calculation of pressure losses is given. In this part, the basic theories of fluid mechanics and the basics of simulations of fluid dynamics are presented. In addition, the gas treatment process is presented to define the position of the cooling stack. With this information, a model for the simulation of the cooling stack is created. First, the assumptions and simplifications are described. In the next step, the effect of the assumptions and simplifications are defined. In addition, the sequence of the simulation will be described. Based on this information, the limits and the accuracy of the model and the system parameters can be identified. Next, the simulation results will be presented. The investigated factors are considered and classified on their importance. In addition, the result of the simulation is being compared with the measurements from reality. An overview of the results and findings of the work is given at the end. The main focus is on the interpretation of the results, since the results of simulations must be viewed critically. In this context, the next steps are identified.